The Lençóis Maranhenses National Park (Parque Nacional dos Lençóis Maranhenses) is located in Maranhão state, in northeastern Brazil, just east of the Baía de São José, between 02º19’—02º45’ S and 42º44’—43º29’ W.
It is an area of low, flat, occasionally flooded land, overlaid with large, discrete sand dunes. It encompasses roughly 1500 square kilometers, and despite abundant rain, supports almost no vegetation.
The park was created on June 2, 1.981.
It was featured in the Brazilian film The House of Sand. Kadhal Anukkal, a song from an Indian film Endhiran starred by Rajnikanth was also shot here.
Located on the eastern coast of the state of Maranhão by the banks of the Preguiças River, the park embraces the municipalities of Humberto de Campos, Primeira Cruz, Santo Amaro and Barreirinhas, the latest serving as the main jumping off point into the protected park.
There are several regular bus/truck routes between Barreirinhas and São Luís, Brazil (Maranhão's capital), a distance of about 260 km.
There are also air taxis from São Luís to Barreirinhas.
The National Park is quite extensive and has no access roads.
Because of the nature of the park's protected status, most vehicles are not permitted access.
Entrance to the park is made exclusively by 4 wheel drive trucks.
Escorted trekking trips and tours are offered by Adventure Life, Bespoke Brazil, and Pantanal Adventures.
Composed of large, white, sweeping dunes, at first glance Lençóis Maranhenses looks like an archetypal desert. In fact it isn't actually a desert.
Lying just outside the Amazon Basin, the region is subject to a regular rain season during the beginning of the year.
The rains cause a peculiar phenomenon: fresh water collects in the valleys between sand dunes, spotting the desert with blue and green lagoons that reach their fullest between july and september.
The area is also surprisingly home to a variety of fish which, despite the almost complete disappearance of the lagoons during the dry season, have their eggs brought from the sea by birds.
The national park status serves only as a means of protecting the area's ecology; consequently many people are park residents, as is also the case with nearby Jericoacoara.
The inhabitants of the park work primarily as fishermen during the rainy season.
During the dry season, many leave for neighboring regions to work small plots of land.